The present invention relates to a block lock for a round link chain.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Some conventional block locks for chains include two approximately L-shaped lock halves connected by pins. Each of the lock halves has a longitudinal leg with a center rib facing away from its continuous back section as well as bearing shells for steel chain links and a cross leg disposed on one end of the longitudinal leg. Projections and receiving pockets are arranged on the end faces of the longitudinal legs that face away from the cross legs, and receiving pockets and projections which match the projections and receiving pockets on the longitudinal legs are arranged on the sides of the cross legs facing the center ribs. The respective projections engage with the corresponding receiving pockets when the link halves are joined after insertion of the end links of two round link chains, thereby locking the link halves with each other. The position of the link halves is secured with a dowel pin which extends transversely through the center ribs of the link halves, meshing in a groove- and spring-like fashion.
Although these conventional block locks have proven successful in practice, potential for improvement still exists in practical applications. These applications relate particularly to underground mining operations, where the round link chains connected by one or several block locks are guided over chain wheels arranged at the ends of the respective equipment (for example, a chain conveyor). When after running over a chain wheel the block locks dip into the region below, a so-called slack chain is formed. The round link chains then no longer experience the tension force exerted by the chain wheels. The end links engaging with the block locks can then strike against the flanks of the center ribs, causing high stress on the dowel pins extending through the center ribs.
It would therefore be desirable and advantageous to address this problem and to obviate other prior art shortcomings by providing a block lock with an improved service life.